Advances in light wave technology have made optical fibers a very popular medium for large bandwidth communication applications. In particular, optical technology is being utilized more and more in broadband systems wherein communications between systems take place on high-speed optical channels. As this trend continues to gain more and more momentum, the need for efficient utilization of the precious real estate on circuit boards, racks/shelves, back planes, distribution cabinets, etc., is becoming ever increasingly important. In order to fulfill expectations across the industry, opto-electronic modules and optic fiber devices need to continue to be made miniaturized or compact, thereby taking full advantage of the maturity of micro- and opto-electronic technologies for generating, transporting, managing and delivering broadband services to ever increasing bandwidth demands of end users at increasingly lower costs. Thus, the industry has placed an emphasis on small optical connectors and optical harnesses, both simple and complex. However, miniaturizing and compacting is tempered by the requirements of transmission efficiency and organization.
With the miniaturization of optical modules and optical fiber devices, the management of optical fiber congestion has become an issue at optical interfaces and connection distribution points. One solution is the use of multi-fiber ribbon in which a plurality of optical fibers are organized and contained side by side in a plastic ribbon. It is known to interconnect these ribbon cables by supporting the fibers between two support members made of a monocrystaline material, such as silicon. In the support members are V-grooves formed utilizing photolithographic masking and etching techniques. The fibers are placed side by side in individual V-grooves of one support member. The other mating support member, having corresponding V-grooves, is placed over the fibers so as to bind or hold the fibers in a high precision spatial relationship between the mating V-grooves. The top and bottom support members sandwiching the multi-fiber ribbon are typically bonded together with a clamp or adhesive, forming a plug of a multi-fiber connector. Two mating plugs with the same fiber spacing may then be placed in an abutting relationship so that the ends of the fibers of the respective plugs are substantially co-axially aligned with one another, thereby forming a multi-fiber connection. If desired, such plugs can be stacked in order to increase the interconnection density. However, in addition to straight connections, in some applications it is desirable to re-route the optical fibers in a multi-fiber ribbon and reconfigure the optical fibers in a new multi-fiber ribbon combination.
Multi-fiber ribbons and connectors have numerous applications in optic communication systems. For instance, optical switches, optical power splitters/combiners, routers, etc., have several input and/or output ports arranged as linear arrays to which a plurality of fibers are to be coupled. Further, since optical fibers are attached somehow to launch optical signals into these devices and extract optical signals therefrom, splicing of arrays of fibers (i.e., a multi-fiber ribbon) to such devices can be achieved using multi-fiber connectors. Another possible application relates to an optical fan-out fabric where an array of fibers in a multi-fiber ribbon may be broken into simplex or duplex channels for distribution purposes, as is often desired.
Yet another multiple fiber application is the perfect shuffle cross-connect, where, for example, each of the multiple input ports, typically comprising more than one optical fiber, is in communication by one fiber with each of the multiple output ports, which also typically comprises more than one optical fiber. The perfect shuffle cross-connect provides for multi-channel optical transmissions, for example as in multi-wavelength transmissions, to be mixed and re-routed in an orderly fashion. Currently, such connections are made by flexible optical circuits or complex jumpers. While complex jumpers take up space and create congestion, the flexible optical circuit is expensive to produce, often requiring highly skilled labor, such as a CAD designer to generate the original drawings of the circuit, and expensive processing machines such as those for fiber routing, lamination and connectorization equipment.
With the development of downsized optical modules and optical fiber devices comes the necessity and challenge of developing connectors for use with such devices.
In summary, there continues to be strong market forces driving the development of fiber optic connection systems that take up less space and relieve congestion, while at the same time demanding that the increasing interconnection density requirements be satisfied. Further, such a connection system should be capable of being manufactured and assembled easily and inexpensively.
Thus, a heretofore-unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
The present invention is an optical harness for an optical cross-connect defined primarily by a first portion and a second portion. The first portion of the optical harness comprises a number M of fiber optic row cables where each fiber optic row cable comprises an array of a number N of fibers arranged on a first plane. The first plane on which each fiber optic row cable is disposed is substantially parallel to each other first plane on which a fiber optic row cable is disposed. The second portion of the optical harness comprises a number N of fiber optic column cables where each fiber optic column cable comprises an array of a number M of fibers arranged on a second plane angularly disposed relative to the first plane. The second plane on which each fiber optic column cable is disposed is substantially parallel to each other second plane on which a fiber optic column cable is disposed. The optical harness further comprises a holding mechanism disposed intermediate the first portion and the second portion of the optical harness. The orientation of the first planes on which the fiber optic row cables are disposed is arranged at a defined angle relative to the second planes on which the fiber optic column cables are disposed. The holding mechanism is arranged and configured to transition the fibers from one configuration toward the first portion to the other configuration toward the second portion and to maintain the relative angled arrangement.
The present invention is also a high-density plug-like optical connector having outer support members and an inner support members, both having an array of substantially parallel grooves for receiving fibers. The outer support members and the inner support members can be stacked to received a plurality of optical fibers in a variety of arrangements.
The present invention can also be viewed as a method for providing an optical cross-connect between a first element and a second element between which distribution or re-routing accurately positioned optical fibers in predetermined configuration is desired. In this regard, the method can be broadly summarized by the following steps: providing a number M of fiber optic row cables having a defined length, where each fiber optic row cable comprises an array of a number N of fibers arranged on a first plane substantially parallel to the first plane of each of the other fiber optic row cables; stacking the number M of fiber optic row cables; disposing a holding mechanism intermediate the defined length of the fiber optic row cables; separating each array of N fibers into individual fibers; re-grouping the fiber optics into a number N of fiber optic column cables, each comprising a number M of fibers; connecting the first portion of the crossconnect to the first element; and connecting the second portion of the cross-connect to the second element. Thus a transition from a plurality, such as twelve, rows of, for example, ten fibers each, to an array of ten columns of twelve fibers each is realized. Each column contains only the fibers, which have common positions in the rows. Thus all number one fibers are in one column, number two fibers in a second column, etc. This makes possible a perfect shuffle cross-connect in a minimum of space and complexity.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention.